B65 High

Johnson Starley B65 Fault Code

The Johnson Starley B65 fault code means: your boiler is waiting for the ventilation fan to spin up before it can safely light the burner, but it hasn't detected any movement yet.. It appears on 3 Johnson Starley models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Waiting for fan to start
Typical repair cost £180-£350 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Johnson Starley models that show the B65 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Johnson Starley B65 fault code information on this page is sourced and cross-checked against the official Johnson Starley service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026